Light bleeding on my fertile week

Eva • 23 years of age

I’m supposed to be on my “fertile” days and I felt discharge while I was walking. I thought nothing of it as I knew I can get extra discharge on these days. I went to the bathroom, wiped and to my surprise it was brown with a little blood clot. What’s happening? I had my period almost two weeks ago. I’ve never had this happen. I’m pretty regular with the occasional 1-3 days difference.